The present invention relates in general to data storage systems such as disk drives, and it particularly relates to a slider and a flexure to which the slider is attached. More specifically, the present invention provides a novel flexure design and assembly process for securing the slider to the flexure by means of a solder fillet bond applied to the leading edge surface of the slider, onto the surface of the flexure.
In a conventional magnetic storage system, a thin film magnetic head includes an inductive read/write element mounted on a slider. The magnetic head is coupled to a rotary actuator magnet and a voice coil assembly by a suspension and an actuator arm positioned over a surface of a spinning magnetic disk. In operation, a lift force is generated by the aerodynamic interaction between the magnetic head and the spinning magnetic disk. The lift force is opposed by equal and opposite spring forces applied by the suspension such that a predetermined flying height is maintained over a full radial stroke of the rotary actuator assembly above the surface of the spinning magnetic disk.
The suspension assembly includes a resilient load beam, and a flexure to which the slider with a magnetic read/write head is attached. The load beam generally directs the slider toward the air bearing surface (ABS) at a predetermined angle. The aerodynamic force generated by the ABS is reacted by the load beam to maintain the slider over the surface of the spinning magnetic disk at a predetermined flying height.
In a conventional magnetic disk drive, the slider is attached to the flexure by means of an adhesive connection at its interface surface with the flexure. A conventional method of attaching the slider to the suspension that is in common use in the industry typically involves creating a permanent adhesive bond between the slider and the suspension. The method of using an epoxy bonding technique is illustrated in FIG. 6.
A disadvantage of the epoxy bonding method emanates from the permanence of the bond in that any attempt to separate the slider from the suspension would typically necessitate breaking the bond and thus inducing a potential irreversible damage to the suspension-flexure assembly.
Various attempts have been made to alleviate the foregoing concern. Slider-suspension assembly technologies such as solder bumping, under-bump metallization, and flip chip are known in the industry for providing solder bonding process in lieu of epoxy bonding.
One such attempt is exemplified by U.S. Pat. No. 4,761,599 to Ainslie et al. that describes a slider-suspension assembly suitable for mechanically and electrically joining the two components using solder bonding. The bonding method uses simultaneous reflow of all solder bumps, which might necessitate global heating of the entire assembly, including the thin film read/write head.
While conventional methods may have addressed and resolved certain aspects of the foregoing concern, they are not completely satisfactory in that the use of discrete solder contact pads requires masking process steps in manufacturing of slider. In addition, global heating to reflow typical solder alloys could require temperature exposure that is incompatible with the temperature limitation of the read/write head. The need for a comprehensive solution has heretofore remained unsatisfied.
It is a feature of the present invention to provide a new method for securing a slider to a suspension assembly for use in a magnetic disk drive data recording device. To this end, a solder fillet bond is applied at the leading edge surface of the slider to provide a structural connection of the slider to the flexure, while also enabling the slider-suspension assembly to be separated without damage during the process.
The use of this and other features of the present invention, in conjunction with a thermally processed electrical connection, enables rework of a reject head on a good suspension.